1.A impeller within the vacuum pump fails causing vehicle faults. 2.Sometimes water ingress can cause problems with these pumps, often however the impeller on the spindle of the motor can break or shatter over time. 3.A broken impeller will cause a lack of air pressure / vacuum to be provided meaning actions of the PSE pump will be inhibited. 4.It can also lead to a jammed motor which will lead to the pump blowing the 20A fuse and shutting off. for Bosch motor part number: 1397220291 Mercedes pump part numbers: A2308000648, A2308000548, A2308000448, A220800348, A2208000648, A2208000748, A2208000548, A2208000848, A2208001148, A2208001248, A2208000948. Fitment: For Mercedes Benz SL-Class (R230) 2001-2011 1st gen: 2001- 2006 - SL350, SL500, SL600, SL55AMG, SL65AMG Facelift 1: 2006 - 2008 - SL350, SL500, SL550, SL600, SL55AMG, SL65AMG Facelift 2: 2008 - 2012 - SL280, SL300, SL350, SL500, SL550, SL600, SL63AMG, SL65AMG For Mercedes Benz S-Class (W220) 1998-2005 S280, S320CDI, S320CDI L, S350, S350 L, S400CDI, S430, S430 L, S500, S500L, S500 4-Matic, S600L, S55 AMG, S55 AMG L For Mercedes Benz CL-Class (C215) 1999-2006 CL500, CL600, CL55AMG, CL63AMG, CL65AMG Material:ABS Colour:black Package Contents: 3 x Motor Impeller Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.